Flamed is actually charred with a blowtorch. A wire brush is used afterward to remove some of the soot and expose the grain. For the seal, it's a typical wood wax (don't recall what was actually used on this project). Talk to a local woodworker or stain shop about what they would recommend.

Regarding the pebbles, I believe the grout is applied, then the majority of it is remove with a stiff bristled brush and then finished with a wet painters brush to smooth it back out. I found this installation guide online from a quick search -> http://www.islandstone.com/mediafiles/product_records/specifications/23_Stacked_Pictorial_and_instructions.pdf